1. Technical Field
This disclosure relates to printed circuit boards (PCBs), and more particularly, to test structures used in PCB's and in coupons on PCB panels.
2. Description of the Related Art
PCBs are used to implement many electronic systems, such as computer systems. A typical PCB includes a number of conductive layers, with the conductive layers being separated from one another by layers of dielectric material. Some conductive layers may be dedicated to power or ground, while other conductive layers may be dedicated to the providing signal paths for connecting the various components to be mounted on the PCB.
Many PCBs may be initially manufactured with structures known as test coupons (or more simply, coupons). A coupon is a structure implemented in a PCB that may be used for some sort of testing during the manufacturing or post-manufacturing (but pre-operational) phase of the PCB. The coupons may thus be separate from the design of the board itself in terms of its operational function. In some cases, the coupons may be implemented on the PCB itself, while in other cases, a coupon may be implemented on a breakaway portion of a panel that is discarded after manufacturing, assembly and testing has been complete.
Coupons may be implemented for a wide variety of tests. For example, coupons may be implemented on a PCB (or breakaway structure attached thereto during manufacturing) for impedance testing, various electrical connection tests, and so on.